Low rate of carriage of macrolide-resistant group B streptococci in pregnant women in The Netherlands

Anouk E. Muller, Arijaan W. Valkenburg-van den Berg, Deborah Kreft, Paul M. Oostvogel, Arwen J. Sprij, Alex van Belkum

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6 Citations (Scopus)


Objectives: To describe prevalence of phenotypic and genotypic macrolide-resistance among GBS isolates in pregnant women and explore the possibility of clonal spread of resistant GBS isolates in a multicultural population. Study design: Antimicrobial resistance patterns of 107 GBS isolates obtained from asymptomatic pregnant women were determined using E-tests. Macrolide resistance genes mef(A), erm(TR) and erm(B) were determined with PCR and a subset of 39 isolates, including the 8 isolates harbouring macrolide resistance genes, was subjected to RAPD analysis to detect clonal spreading. Results: Resistance to erythromycin and clindamycin was found in 8% and 7%, respectively. Macrolide resistance genes mef(A), erm(TR) and erm(B) were found in 1, 2 and 5 isolates, respectively; only five of these eight isolates exhibited both genotypic as well as phenotypic resistance. One genotype occured in 36% of the subset. Conclusions: Earlier reports on prevalence of phenotypic resistance were confirmed. Among the susceptible isolates one clonal type of GBS was clearly predominant; one of the resistant isolates shared its genotype. When such clonal types acquire resistance traits in the future, GBS disease may become harder to control.

Original languageEnglish
Pages (from-to)17-20
Number of pages4
JournalEuropean Journal of Obstetrics and Gynecology and Reproductive Biology
Issue number1
Publication statusPublished - Mar 2008


  • Clonal spread
  • Group B streptococcus
  • Phenotypic and genotypic resistance

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